A/T - AEGS System Improved

Group 24
Automatic Transmission



Bulletin Number
24 02 89 (1860)



Woodcliff Lake, NJ
April 1989
Technical Dept.



SUBJECT:
4HP 22EH and 4HP 24EH Transmissions

MODELS:
535iA, 735iA, 735iLA, 750iL
(Produced from approximately Mid-November 1988)

Situation:
As of the 1989 Model Year, the vehicles listed above are equipped with an improved version of the AEGS, Electronic Hydraulic Transmission.

The new AEGS System is designated "E9" and the major components such as the transmission, wiring harness and control unit are not interchangeable with the previous version.

The new E9 version provides high speed downshift protection and a changed control of the reverse lockout feature.

Identification:
The E9 AEGS System was phased into the 1989 models during September/November 1988. Consequently, it is not possible to use a production date alone to determine the previous or new status of a vehicle's AEGS transmission system.





A visual inspection should be used to identify the AEGS version.



Parts Information:

The current parts system microfiches list the E9 introduction as from 11/88. As previous information indicates, this date should only be used as a guideline denoting E7 or E9 System equipment.

The actual determination of the AEGS version must be made by the repairing technician using the information listed in this bulletin.

Fault Diagnosis:








For complete E9 System troubleshooting and operation information see Section 24 of the E34 Diagnostic Procedures Manual (DDT 9/88). The two wiring diagrams show the wiring change between the the E7 and E9 Systems.

Warranty Status:

Information only.